diff --git a/requirements_dev.txt b/requirements_dev.txt
index 70e8504..8eada6d 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,12 +1,12 @@
-pip==18.1
+pip==19.0.1
 bumpversion==0.5.3
 wheel==0.32.3
 watchdog==0.9.0
 flake8==3.6.0
-tox==3.6.1
+tox==3.7.0
 coverage==4.5.2
 Sphinx==1.8.3
-cryptography==2.4.2
+cryptography==2.5
 PyYAML==3.13
 twine==1.12.1